pub mod person {

    pub struct Person {
        do_something: String,
    }

    pub trait Person2 {
        fn say(&self);
        fn do_something(do_thing: String) -> String;
    }

    impl Person2 for Person {
        fn say(&self) {
            println!("{:}", self.do_something);
        }
        fn do_something(i: String) -> String {
            i
        }
    }
}
